On Tue, Oct 20, 2020 at 2:45 PM Rouven Czerwinski <r.czerwinski@xxxxxxxxxxxxxx> wrote: > > On Tue, 2020-10-20 at 14:22 +0200, Robert Carnecky (Neopsis) wrote: > > On Tue, Oct 20, 2020 at 6:04 AM Rouven Czerwinski > > <r.czerwinski@xxxxxxxxxxxxxx> wrote: > > > On Tue, 2020-10-20 at 05:59 +0200, Rouven Czerwinski wrote: > > > > On Tue, 2020-10-20 at 00:29 +0200, Robert Carnecky (Neopsis) > > > > wrote: > > > > > On Mon, Oct 19, 2020 at 11:28 AM Ahmad Fatoum < > > > > > a.fatoum@xxxxxxxxxxxxxx> wrote: > > > > > > Hello, > > > > > > > > > > > > On 10/18/20 1:17 AM, Robert Carnecky (Neopsis) wrote: > > > > > > > On Sat, Oct 17, 2020 at 11:29 PM Ahmad Fatoum < > > > > > > > a.fatoum@xxxxxxxxxxxxxx> wrote: > > > > > > > > Hi, > > > > > > > > > > > > > > > > On 10/17/20 1:31 PM, Robert Carnecky (Neopsis) wrote: > > > > > > > > > Finally, I managed to boot into barebox menu using > > > > > > > > > UART1 > > > > > > > > > (/dev/ttyS0) > > > > > > > > > as the console. The solution was to remove all UART > > > > > > > > > related > > > > > > > > > overlays > > > > > > > > > from config.txt and only activate UART1. > > > > > > > > > > > > > > > > > > enable_uart=1 > > > > > > > > > > > > > > > > > > Anyway, another problem occurred. When booting via > > > > > > > > > barebox > > > > > > > > > the CPU > > > > > > > > > serial number is wrong. Obviously, barebox somehow > > > > > > > > > manipulates the > > > > > > > > > internal structures and > > > > > > > > > > > > > > > > > > cat /proc/cpuinfo > > > > > > > > > > > > > > > > > > returns always > > > > > > > > > > > > > > > > > > Hardware : BCM2835 > > > > > > > > > Revision : 0000 > > > > > > > > > Serial : 0000000000000000 > > > > > > > > > Model : Raspberry Pi Compute Module 3 > > > > > > > > > IO > > > > > > > > > board V3.0 > > > > > > > > > > > > > > > > > > When I boot the same image directly without barebox > > > > > > > > > boot > > > > > > > > > loader, the > > > > > > > > > info is OK. I found some discussions about U-Boot and > > > > > > > > > wrong serial > > > > > > > > > number here > > > > > > > > > > > > > > > > > > > > > > > > > > > https://www.raspberrypi.org/forums/viewtopic.php?t=183474#p1162778 > > > > > > > > > > > > > > > > > > maybe that's barebox related too. Anyway, that is a > > > > > > > > > definitive no go > > > > > > > > > with barebox for us because parts of our software are > > > > > > > > > expecting the > > > > > > > > > unique serial number. > > > > > > > > > > > > > > > > I believe you can boot Linux with /vc.dtb and you'll get > > > > > > > > the > > > > > > > > same > > > > > > > > device tree passed to Linux as if you booted without > > > > > > > > passing > > > > > > > > through > > > > > > > > barebox. > > > > > > > > > > > > > > Yes, but then I lose my Linux console! A summary, in all > > > > > > > cases > > > > > > > Barebox device > > > > > > > tree in arch/arm/dts/bcm2837-rpi-cm3.dts was updated > > > > > > > following > > > > > > > your hint, e.g. > > > > > > > > > > > > > > / { > > > > > > > chosen { > > > > > > > stdout-path = "&uart1"; > > > > > > > }; > > > > > > > }; > > > > > > > > > > > > > > &uart1 { > > > > > > > pinctrl-names = "default"; > > > > > > > pinctrl-0 = <&uart1_gpio14>; > > > > > > > status = "okay"; > > > > > > > }; > > > > > > > > > > > > > > &uart0 { > > > > > > > pinctrl-names = "default"; > > > > > > > pinctrl-0 = <&uart0_gpio32>; > > > > > > > status = "okay"; > > > > > > > }; > > > > > > > > > > > > > > 1. Booting kernel direct, works as expected (console on > > > > > > > uart1), > > > > > > > expected behavior > > > > > > > > > > > > > > kernel=zImage > > > > > > > enable_uart=1 > > > > > > > dtoverlay=uart0,txd0_pin=32,rxd0_pin=33,pin_func=7 > > > > > > > dtoverlay=uart1,txd1_pin=14,rxd1_pin=15 > > > > > > > > > > > > > > 2. With Barebox loader. The same config.txt as in case 1), > > > > > > > - no Barebox console > > > > > > > - kernel boots with the console on uart1 > > > > > > > > > > > > > > kernel=barebox-raspberry-pi-cm3.img > > > > > > > enable_uart=1 > > > > > > > dtoverlay=uart0,txd0_pin=32,rxd0_pin=33,pin_func=7 > > > > > > > dtoverlay=uart1,txd1_pin=14,rxd1_pin=15 > > > > > > > > > > > > > > 3. With Barebox loader, no uart overlays in config.txt. > > > > > > > - Barebox console on uart1 ok, > > > > > > > - kernel console on uart1 > > > > > > > - almost done), but ... no cpuinfo > > > > > > > > > > > > > > kernel=barebox-raspberry-pi-cm3.img > > > > > > > enable_uart=1 > > > > > > > > > > > > > > 4. With Barebox loader, no uart overlays in config.txt, > > > > > > > Linux > > > > > > > boots with vc.dtb. > > > > > > > - Barebox console on uart1 ok > > > > > > > - no Linux console, Linux boots with cpuinfo ok > > > > > > > > > > > > > > kernel=barebox-raspberry-pi-cm3.img > > > > > > > enable_uart=1 > > > > > > > > > > > > > > I did not found any combination when I get the Barebox > > > > > > > console > > > > > > > and > > > > > > > Linux console on uart1 > > > > > > > and with cpuinfo ok. If the serial number is not needed, > > > > > > > case > > > > > > > 3) should be ok. > > > > > > > > > > > > What happens if you combine 2. and 4. ? > > > > > > So you have enable_uart=1, the uart overlays _and_ Linux > > > > > > boots > > > > > > with vc.dtb? > > > > > > > > > > Negativ. Whenever I enable overlays in the config.txt that map > > > > > uart0 > > > > > to pin32/33 and > > > > > uart1 to pin 14/15 (console), I do not get Barebox console. It > > > > > does > > > > > not depend on the device > > > > > tree passed to the kernel. This interaction between Barebox > > > > > device > > > > > tree and Raspberry config.txt > > > > > overlays is a bit strange for me. > > > > > > > > > > Just an idea - does Barebox fully support this hardware? From > > > > > the > > > > > 2835 > > > > > ARM Peripherals Guide, > > > > > chapter 2.2 miniUART : > > > > > > > > > > > The implemented UART is not a 16650 compatible UART However > > > > > > as > > > > > > far as possible > > > > > > the first 8 control and status registers are laid out like a > > > > > > 16550 UART. Al 16550 register > > > > > > bits which are not supported can be written but will be > > > > > > ignored > > > > > > and read back as 0. > > > > > > All control bits for simple UART receive/transmit operations > > > > > > are > > > > > > available. > > > > > > > > > > Barebox has support for NS16650 ( CONFIG_DRIVER_SERIAL_NS16550) > > > > > but > > > > > not for > > > > > Raspberry miniUART. > > > > > > > > > > Anyway, I am giving up. I am sure I tested all combinations of > > > > > overlays, I have written my > > > > > own dts, nothing works as I need (console=uart1, incl. proper > > > > > serial > > > > > number handling). > > > > > There is no problem to get the console on uart0/ttyAMA0, but > > > > > not on > > > > > uart1/ttyS0. > > > > > The Raspberry way how they are handling uarts lacks all logic > > > > > and > > > > > is completely > > > > > unclear. > > > > > > > > Hi, > > > > > > > > looking into arch/arm/dts/bcm2837-rpi-cm3.dts: > > > > / { > > > > chosen { > > > > stdout-path = &uart0; > > > > }; > > > > }; > > > > > > > > The CM3 module is currently default configured to use uart0 as > > > > the > > > > stdout path, while bcm2837-rpi-3.dts is configured for uart1. > > > > This was done in ab76f9d09d3b7b77fc00d84bc2fac6bfbf82c69c after > > > > the > > > > miniuart support was added to the NS16550 driver > > > > in 77de547cd179b910cdcb8530df15d77a0fc66a3c. > > > > > > Disregard this, I didn't read the whole thread. There however was > > > another user who tried to use the miniuart and had failures on > > > probe on > > > the CM3. Unfortunately the barebox archives don't have these mails, > > > I'll attach an mbox which has the whole thread. > > > > > > > > > Regards, > > > Rouven Czerwinski > > > > > > > The thread sent by Rouven describes really the same issue and, like > > me, without a solution. > > As I wrote in my summary, there is one combination of config.txt and > > barebox > > device tree booting into barebox console on uart1 and kernel console > > on uart1: > > > > barebox device tree: > > > > / { > > chosen { > > stdout-path = "&uart1"; > > }; > > }; > > > > &uart1 { > > pinctrl-names = "default"; > > pinctrl-0 = <&uart1_gpio14>; > > status = "okay"; > > }; > > > > &uart0 { > > pinctrl-names = "default"; > > pinctrl-0 = <&uart0_gpio32>; > > status = "okay"; > > }; > > > > > > config.txt: > > kernel=barebox-raspberry-pi-cm3.img > > enable_uart=1 > > > > Unfortunately, in this case the content of /proc/cpuinfo in Linux > > is wrong, > > which is in my opinion barebox bug. > > According to [1], the serial number is directly read from the device > tree, this node is not populated by barebox. This leaves the following > possible options: > > 1) Fix the barebox NS16550 driver to probe on the rpi3 CM3 miniuart. > Then boot with the vc.dtb file. > > 2) Read the serial-number from the vc.dtb file and fixup the serial > number before booting with the barebox device tree > > 3) Find out if the RPI serial number can be read using the mailbox > communication interface to the VC core, retrieve the number and fix it > up into the device tree before boot. A quick google says this could be > the case, see [2]. > > [1]: > https://elixir.bootlin.com/linux/latest/source/arch/arm/kernel/setup.c#L951 > [2]: > https://github.com/Terminus-IMRC/mailbox/blob/b96aa3cc8dfee2be2c8f835e09e812000910a5ff/src/wrap_ours.c#L114 > > Regards, > Rouven > OK, I did not know that barebox do not populate the serial number. I will do it in my app from the mailbox. FYI I found various ways how to read the S/N here https://github.com/AndrewFromMelbourne/raspi_serialnumber Robert _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
